Coat a muffin pan with butter, oil, or line with baking cups.
Add garlic and let cook 1 to 2 minutes until fragrant, stirring frequently.
Be sure your tins are well oiled! Just to be safe, and to provide extra portability, I typically use baking cups to line my muffin tin. If you prefer to cook the frittata whole instead of individually, use a 9-inch square baking dish and bake at 350°F for 40 to 50 minutes until eggs are set. Use cookie cutters if you want to make fun shapes!
The combinations for frittata are endless! The sweet potato adds moistness to the frittata which I love. The chard brings an earthy flavor to complement the sweetness. Other root vegetables such as parsnips or carrot would be a good alternative for the sweet potato. You could also use kale or finely diced broccoli instead of chard in this frittata muffin recipe.